intellij extend java syntax highlighting

Hi,

I would like to know how to extend java syntax highlighting and parsing using an ideaj plugin. I have managed to write a custom language by following a JetBrains tutorial. but I cannot find any documentation on how to get the existing java syntax highlighting and parsing in ideaj CE and extend them in my plugin.

I have also asked this question on stackoverflow 

I would greatly appreciate if someone can point me to some instructions.

Thank You.